Technical Field
The present disclosure relates to an optical device. More particularly, the present disclosure relates to an optical device utilized for measuring distances.
Description of Related Art
With the rapid development of high technology industry, the demand for positioning systems in the scale of micrometers and nanometers has been increasing. In addition, the demand for the precision of the optical scales has been relatively increasing as well. Furthermore, the application of optical scales has become more popular.
Therefore, apart from increasing the precision of the optical scales, the effective reduction for the production cost of the optical scales is no doubt an important issue in the industry.